Experience of dermatologic biologic therapy use and associated opportunistic infection management in Australia's tropical north.

Abstract

Royal Darwin Hospital (RDH)is the sole public dermatology service in the Northern Territory (NT). Prescription of biologic therapies (BT) in the NT is uniquely challenging, with remote populations carrying a high tropical disease burden. The aim of this audit is to examine the demographics and outcomes of patients on BT for dermatologic conditions. Retrospective case note review of patients receiving BT through the RDH Dermatology department between August 2021 and October 2023. Data analysed were demographics, location, dermatological diagnosis and serology status. In this audit, 115 patients were included. Age range of 13-91 years, mean of 51.1 years (±14.7), 52 (45.2%) patients were female and 8 (7.8%) identified as First Nations Australian. A large geographical area was serviced, with a primary address between 1 and 1496 km from RDH. Eighteen patients (15.7%) have discontinued BT completely. There was a statistically significant relationship between cessation of BT and increased distance of primary residence from RDH (p < 0.0007). Eighteen patients (15.7%) required management of infections identified in opportunistic infection screening. These infections were strongyloidiasis, tuberculosis, melioidosis and hepatitis B. There is significant anxiety surrounding BT and tropical infections, including in returning travellers in southern Australian states. There has been particular interest in strongyloidiasis infection, as dupilumab acts on the Th2 immunity mechanism critical to parasitic infection response. This audit exhibits the unique experience of dermatological care in a tropical setting, demonstrating how BT can be used safely and how, when identified, these tropical infections can be successfully managed.